16528
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 10
- Divisor Sum
- 32054
- Proper Divisor Sum (Aliquot Sum)
- 15526
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8256
- Möbius Function
- 0
- Radical
- 2066
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 159
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- a(1) = 7; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.at n=36A025006
- Row sums of triangle in A077569.at n=14A077570
- In binary representation: numbers not occurring in their factorial.at n=41A093685
- Numbers k such that the reverse of the representation of phi(k) is a substring of k, in base 10.at n=11A113622
- Concatenating n with n+1 (in base 10) gives a number which is the product of 2 palindromes.at n=14A113942
- Records in A118878.at n=9A119903
- Natural number transform of Aitken's triangle.at n=32A127740
- Numbers k such that there are 15 primes between 100*k and 100*k + 99.at n=21A186407
- G.f. satisfies: A(x) = Product_{n>=0} (1 + x*(x+x^2)^n)/(1 - x*(x+x^2)^n).at n=13A192627
- Number of length 3 0..n arrays with each partial sum starting from the beginning no more than two standard deviations from its mean.at n=24A244834
- Number of length n+2 0..1 arrays with the sum of the maximum minus the median of adjacent triples multiplied by some arrangement of +-1 equal to zero.at n=12A251928
- Array read by antidiagonals: T(n,k) = number of noncrossing path sets on k*n nodes up to rotation and reflection with each path having exactly k nodes.at n=47A302828
- Number of pairwise coprime strict compositions of n, where a singleton is not considered coprime unless it is (1).at n=46A337561
- a(n) = Sum_{d|n} d^(n/d - d) * binomial(n/d-1,d-1).at n=23A376021
- Numbers that can be written as a^2 + 3*b^2 for some a, b in A155716 and also as c^2 + 6*d^2 for some c, d in A092572.at n=12A380295